Conventionally, there is used a damper pulley that is coupled, for example, to a crankshaft of the engine of a vehicle and absorbs torsional vibrations caused in association with the rotation of the crankshaft. The damper pulley has a structure in which a metallic pulley is concentrically coupled through a damper rubber made of an annular elastic body to the outer periphery of a metallic hub fixed to the crankshaft. As a method for manufacturing this damper pulley, a manufacturing method described in Patent Document 1 is known.
In the damper pulley manufacturing method described in Patent Document 1, an elastic body molded of a rubber elastic material in an annular shape is disposed in a state of being loosely fitted, between an outer peripheral tubular portion formed in the shape of a conical tube on the outer peripheral portion of a hub made of a compact of a metallic plate and an annular mass body concentrically disposed on the inner periphery side, and this outer peripheral tubular portion is drawn toward the inner periphery side into a cylindrical shape, whereby the outer peripheral tubular portion, the elastic body and the annular mass body are pressure-welded together. After this drawing process, finishing of a pulley groove formed on the outer peripheral surface of the outer peripheral tubular portion is performed by rolling.
According to this damper pulley manufacturing method described in Patent Document, it is considered that since the process of disposing the elastic body between the outer peripheral tubular portion of the hub and the annular mass body and the process of providing the elastic body with precompression are separate from each other, the elastic body can be fitted between the outer peripheral tubular portion of the hub and the annular mass body in an appropriate radially compressed state without the use of a method such that the elastic body is press-fitted between the outer peripheral tubular portion of the hub and the annular mass body from one side in the axial direction and this facilitates the manufacture of a fitting type damper pulley.